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False CPU Fan Error/Old MoBo

One of the fans in our 5+ year-old HP Pavilion was dying. I opened up the case and decided it was the CPU fan. I ordered a Thermaltake TR2-R1 to replace the stock heatsink and fan. That worked like a charm except that it was the fan on the GPU that was dying (now fixed), a fact I could have discovered if I had a better ear or had I been more careful in my original diagnosis. Live and learn.

Since I installed the TR2-R1, I am getting a false "CPU fan failure error" on startup. The fan is working on visual inspection. I can use "F2" to bypass the error, and fan speeds and temperatures are normal when checked with SpeedFan. When I momentarily plug the old stock heatsink and fan into the mobo, the machine boots fine. It seems beyond question that the problem is the mobo is not sensing the new fan properly.

The BIOS does not have an option to disable the fan sensor, which was still true after I upgraded (probably because this is all proprietary HP stuff). The mobo is an old ASUS model that the company made for HP (A8AE-LE), so very little support or information is available for it.

I am about to give up and just reinstall the old fan and heatsink. The new one is much quieter and would be nice to keep. If anyone has any suggestions, that would be most appreciated. Further specs:

OS Name Microsoft Windows XP Professional
Version 5.1.2600 Service Pack 3 Build 2600
OS Manufacturer Microsoft Corporation
System Manufacturer HP Pavilion 061
System Model PX191AV-ABA d4100e
System Type X86-based PC
Processor x86 Family 15 Model 39 Stepping 1 AuthenticAMD ~2188 Mhz
BIOS Version/Date Phoenix Technologies, LTD 3.15, 1/25/2007
SMBIOS Version 2.4
Total Physical Memory 2,560.00 MB
Available Physical Memory 1.49 GB
Total Virtual Memory 2.00 GB
Available Virtual Memory 1.95 GB
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  1. Thank you, scout_03. Yes, that is my motherboard.

    The diagram gave me the idea of trying the CPU fan in the spot for the chassis fan. I didn't expect much, but I'm getting desperate. Still didn't work. I replugged the CPU fan back into the plug marked "CPU_FAN1" in the layout.

    BTW, one other thing I can add is that right after pushing the "on button," it seems like electricity might be going through the system for about 0.5 seconds (at most) before the fan starts. I wonder if that is the source of the false error message?
  2. post the link of the fan
  3. could be the fan itself defective do you have another computer to try it also did you clean the old paste and put new one before install of new fan and cooler
  4. I did clean the old paste and put new before install. But,it is not the actual cooling that is a problem. Leaving the new heatsink and fan in place, I plugged the old fan into the "CPU_FAN" plug on the motherboard and restarted just long enough to verify that I could get past the "CPU fan failure" error with the old fan.

    It seems pretty likely that the problem lies in the fact that the sensor on the motherboard is not communicating with this particular fan. Maybe the fan is defective, but I don't have any way to test the fan. It does seem to be working in every other way.

    Thanks for trying, Scout_03. Unless someone else comes up with an obvious solution I'm missing, I'll try to see if I can get any help from Thermaltake. If I get any info, I'll report back here.
  5. just aks for rma for the fan
  6. Best answer
    I would check just the fan on another system. That fan is rated to only spin @ 1300 rpms. This is too slow for HP's liking(may even be slower since the board slows the fan down.)

    I see you tried it on the case fan header. Have you tried the case fan on the cpu fan header and the cpu fan on the case fan header.

    To be honest if the case fan will satisfy the cpu fan headers need to see a faster fan, i would run the cpu fan off the power supply since at 1300rpm it should not be too loud and will cool better.
  7. Update: The manufacturer's response was not helpful (not surprisingly).

    Nukemaster's suggestion of trying the case fan on the cpu fan header was an excellent idea, but it did not solve the problem. The motherboard only wants to work with the oem CPU fan. I would not have thought 1300 rpm was too low for the motherboard.

    Thank you, everyone, for your help. This is not worth more time. I am going to put the oem fan and heatsink back in and RMA the new one. Btw, I'm assuming it is always smart to clean the existing thermal paste and then apply new thermal paste whenever one is removing and then reinstalling the heatsink?
  8. SlurmRacer said:
    I'm assuming it is always smart to clean the existing thermal paste and then apply new thermal paste whenever one is removing and then reinstalling the heatsink?

    Yes, you should clean and replace the thermal paste.
  9. OK, so I couldn't let it rest and just RMA a part that should have worked. I tinkered around with it and got things working. Nukemaster's excellent suggestion was to try the case fan on the cpu header and the cpu fan on the case fan header. It suddenly dawned on me that in this configuration the cpu fan was just causing a new error on the case fan header.

    The solution was to bypass the motherboard entirely with the cpu fan entirely and plug the cpu fan directly into the psu. Then, I took a spare case fan and plugged it into the cpu fan header. The second case fan is now just taking up space in a drive bay because this old oem case had no place for a second case fan, but it is satisfying the motherboard's need to see a fan spinning at a high rpm.

    Thank you for your help.
  10. Best answer selected by SlurmRacer.
  11. This topic has been closed by Mousemonkey
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